package demo4.mapper;

import demo4.pojo.User;
import demo4.util.IDBUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.sql.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

@Component
public class UserMapper implements IUserMapper{
    @Autowired
    private IDBUtil dbUtil;

    @Override
    public int insert(User user) {
//        System.out.println("UserMapper:向数据库插入用户信息...");
        try (Connection connection = dbUtil.getConnection();){
            String sql = "INSERT INTO user(username,password,nickname,age) " +
                    "VALUES(?,?,?,?)";
            PreparedStatement ps = connection.prepareStatement(sql);
            ps.setString(1, user.getUsername());
            ps.setString(2, user.getPassword());
            ps.setString(3, user.getNickname());
            ps.setInt(4, user.getAge());
            return ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return 0;
    }

    @Override
    public User selectByUsername(String name) {
        try (Connection connection = dbUtil.getConnection();){
            String sql = "SELECT id,username,password,nickname,age " +
                    "FROM user " +
                    "WHERE username=?";
            PreparedStatement ps = connection.prepareStatement(sql);
            ps.setString(1, name);
            ResultSet rs = ps.executeQuery();
            if(rs.next()){
                User user = new User();
                user.setId(rs.getInt("id"));
                user.setUsername(rs.getString("username"));
                user.setPassword(rs.getString("password"));
                user.setNickname(rs.getString("nickname"));
                user.setAge(rs.getInt("age"));
                return user;
            }

        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    public List<User> selectAll() {
        List<User> userList = new ArrayList<>();
        try (Connection connection = dbUtil.getConnection();){
            Statement statement = connection.createStatement();
            String sql = "SELECT id,username,password,nickname,age " +
                    "FROM user";
            ResultSet rs = statement.executeQuery(sql);
            while(rs.next()){
                User user = new User();
                user.setId(rs.getInt("id"));
                user.setUsername(rs.getString("username"));
                user.setPassword(rs.getString("password"));
                user.setNickname(rs.getString("nickname"));
                user.setAge(rs.getInt("age"));
                userList.add(user);
            }

        } catch (SQLException e) {
            e.printStackTrace();
        }
        return userList;
    }
}










